Page kidney after renal allograft biopsy: sonographic findings

What can go wrong when doing right? A pictorial review of iatrogenic genitourinary complications

A growing number of treatments for genitourinary diseases can result in various iatrogenic complications. Multimodality imaging in the post-procedural setting is essential for early and accurate diagnosis to limit morbidity and mortality. We review common and uncommon treatment-induced pathologies affecting the genitourinary system via a case-based approach. We illustrate notable complications affecting the kidneys, ureters, bladder, and urethra induced by percutaneous procedures, external beam radiation, immunotherapy, laparoscopic/robotic pelvic surgery, and intravesicular BCG. Finally, we provide guidance on optimal imaging techniques for diagnosis and highlight the role of image-guided interventions for mitigation of complications.

Renal tamponade in a patient with hydronephrosis-related Page kidney

A 48-year-old woman presented with hyperreninemic hypertension and renal dysfunction and was diagnosed with hydronephrosis-related Page kidney. The pathophysiology was "renal tamponade", in which the kidney was compressed by the renal pelvis and Gerota's fascia, resulting in intrarenal microvascular ischemia. Ureteral stent placement promptly improved the hyperreninemic hypertension and renal dysfunction, and additional perirenal fluid drainage gradually improved these conditions. These observations indicated the following three points. First, renal compression-induced renin-angiotensin-aldosterone system upregulation plays an important role in the pathogenesis of Page kidney. Second, physicians should consider perirenal fluid drainage as a therapeutic option in addition to ureteral stenting in patients with hydronephrosis-related Page kidney. Third, bilateral perirenal subcapsular hematomas in this case could be caused by hydronephrosis. Hydronephrosis-induced intrarenal pressure elevation possibly caused chronic perirenal subcapsular hemorrhage at the vulnerable sites of the renal cortex and peeling of the renal capsule from the cortex, resulting in the bilateral massive subcapsular hematomas and Page kidney.

Acute Renal Failure in Kidney Transplantation Due to Subcapsular Hematoma After a Renal Allograft Biopsy: Report of Two Cases and Literature Review

The compression of the renal parenchyma due to a subcapsular hematoma, also known as the "Page kidney," is a potentially serious but treatable complication of renal biopsy. Hypertension is very common and, in some cases, renal failure may be present. In kidney transplantation, it is a not well-described entity. Rapid intervention is essential to avoid irreversible damage of the graft and preserve its function. We report 2 cases of acute renal failure due to Page kidney in patients with renal transplant after a percutaneous biopsy with successful recovery after surgical treatment. In addition, we conducted a literature review in order to describe the clinical characteristics of this infrequent complication in patients with a history of renal transplant.

Imaging non-vascular complications of renal transplantation

In patients with end-stage renal disease, the treatment of choice for most patients is renal transplantation. Complications that occur after kidney transplant can be broadly divided into vascular and non-vascular categories. Non-vascular complications can further be divided into surgical and medical categories. When evaluating renal transplant imaging, it is helpful to consider the occurrence of complications in a timeline from time of surgery. Ultrasound is often the first modality used for evaluation of renal transplants particularly in the early postoperative period. Contrast-enhanced ultrasound can be a helpful adjunct in evaluating certain complications such as hematoma, rejection, and infection. Computed tomography (CT) is also helpful in accurately diagnosing complications. Surgical complications include perinephric fluid collections (hematoma, urinoma from urine leak, abscess, and lymphocele), urinary obstruction, and incisional fluid collections and hernias. One major category of medical complications that affect the renal parenchyma includes rejection (hyperacute, acute, and chronic), delayed graft function, acute tubular necrosis (ATN), and nephrotoxicity. Infection, renal calculi, and neoplasms such as post-transplant lymphoproliferative disease are medical complications that occur after renal transplantation. It is important for radiologists to be aware of the ultrasound and CT findings of the surgical and medical complications after renal transplant for prompt identification and treatment.

Page kidney secondary to subcapsular hematoma following percutaneous renal allograft biopsy

Percutaneous renal biopsy with ultrasound guidance is a helpful procedure regularly performed to obtain renal tissue diagnosis for rejection in the postrenal transplant setting; however, it is not without risks. We report the case of a 42-year-old male with end stage renal disease who developed a subcapsular hematoma, with subsequent hypertension and renal failure, compatible with acute page kidney as a complication of the renal biopsy. The ultrasound images demonstrated classic imaging appearances which all diagnostic and interventional radiologists should be aware of. The patient was managed successfully with conventional open surgical evacuation of the hematoma with return to baseline laboratories and vital signs after the procedure.

Allograft loss from acute Page kidney secondary to trauma after kidney transplantation

We report a rare case of allograft loss from acute Page kidney secondary to trauma that occurred 12 years after kidney transplantation. A 67-year-old Caucasian male with a past surgical history of kidney transplant presented to the emergency department at a local hospital with left lower abdominal tenderness. He recalled that his cat, which weighs 15 lbs, jumped on his abdomen 7 d prior. On physical examination, a small tender mass was noticed at the incisional site of the kidney transplant. He was producing a normal amount of urine without hematuria. His serum creatinine level was slightly elevated from his baseline. Computer tomography revealed a large subscapular hematoma around the transplant kidney. The patient was observed to have renal trauma grade II at the hospital over a period of three days, and he was finally transferred to a transplant center after his urine output significantly decreased. Doppler ultrasound demonstrated an extensive peri-allograft hypoechoic area and abnormal waveforms with absent arterial diastolic flow and a patent renal vein. Despite surgical decompression, the allograft failed to respond appropriately due to the delay in surgical intervention. This is the third reported case of allograft loss from acute Page kidney following kidney transplantation. This case reinforces that kidney care differs if the kidney is solitary or a transplant. Early recognition and aggressive treatments are mandatory, especially in a case with Doppler signs that are suggestive of compression.

Acute Urinary Tract Disorders

Acute urinary tract disorders often manifest as flank pain and are a common complaint of patients who present to the emergency department. The pain is often a vague, poorly localized sensation that may have a variety of causes. Laboratory and clinical findings, such as hematuria, are neither sensitive nor specific for determining the cause of the flank pain. Accordingly, imaging is an important tool in determining a diagnosis and management plan. Patients with acute urinary tract disorders who present with pain include those with calculi as well as renal infection, vascular disorders, and hemorrhage.

Page kidney of renal allograft following blunt trauma

We report a case of the Page kidney phenomenon which occurred in a patient with a renal allograft following blunt trauma. The injury occurred following an accidental trip resulting in a trivial fall. The patient presented with acute graft dysfunction with no localizing symptoms or signs. His renal function deteriorated further and he also became hypertensive. Serial ultrasounds showed an increase in the size of perinephric hematoma and evidence of renal compression. Prompt surgical evacuation of the hematoma was performed and renal function returned to baseline. Serial ultrasound examinations and timely surgical intervention can prevent graft loss in this unusual situation.

Ultrasound-guided percutaneous renal biopsy in 295 children and adolescents: role of ultrasound and analysis of complications

Introduction

Percutaneous renal biopsy (PRB) is a decisive diagnostic procedure for children and adolescents with renal diseases. Aim of this study was to evaluate retrospectively the complication rates of percutaneous kidney biopsies and their therapeutic consequences to assess the role of ultrasound-guidance including Doppler ultrasound examinations in preparation, execution and follow-up care and to present a recommended protocol.

Patients and Methods

Institutional review board approved this retrospective study; informed consent was waived. Between 1997 and 2011 a total of 438 ultrasound-guided biopsies were performed in 295 patients, 169 of the biopsies were performed on kidney transplants. Average age of patients was 10.2+/−5.2 years (range of 15 days until age of 23). Before and post biopsy ultrasound examination including Doppler examination was carried out. Biopsy itself was ultrasound monitored. Complications were analysed with regard to age of patient, kidney transplants, year of occurrence, number of punctures, performing physician and time interval of occurrence to develop an optimized protocol for ultrasound-guidance.

Results

In 99% of cases successful PRB were performed, i.e. enough kidney parenchyma for histological analysis was obtained. No lethal or major complication that required surgical intervention occurred. Eighteen relevant complications were observed (complication rate: 4.1%). Except in one case in which additional MRI diagnostic was necessary, ultrasound examination after 4 hours post biopsy or even earlier when symptoms occurred, was able to detect complications and determine indications for intervention.

Conclusion

Ultrasound-guided PRB is an established and effective method in children and adolescents, but shows a certain rate of complications and therefore should not be indicated without diligence. Ultrasound including Doppler ultrasound is a valuable tool in preparation, guidance of biopsy, detection of complications and in follow-up care. Ultrasound examinations (including Doppler) pre-, during and 4 hours post kidney biopsy and, depending from case, a few days until weeks after biopsy is recommended.

Page Kidney

Page kidney refers to the development of secondary hypertension due to compression of the kidney by an external source, most commonly a subcapsular hematoma. Compression of the renal parenchyma results in hypoperfusion and microvascular ischemia leading to activation of the renin-angiotensin system and elevation of blood pressure. Until the last decade, Page kidney was primarily diagnosed in young men with unexplained hypertension and a history of sports-related trauma and imaging studies demonstrating a subcapsular hematoma. Treatment varies from conservative, medical management to a nephrectomy, depending on how the patient’s blood pressure responds to treatment.

Page kidney: etiology, renal function outcomes and risk for future hypertension

The initial description of Page kidney, a form of renin-mediated hypertension, included athletes with renal subcapsular hematoma after flank trauma. Subsequently, nontraumatic etiologies were identified. In this study, the authors compare traumatic and nontraumatic causes of Page kidney. All cases with hypertension attributable to renal hematoma at our institution from 1960 to 2010 were reviewed. Twenty-six patients (9 trauma, 17 nontrauma), with a mean age of 36.7 years, were included. Trauma patients were younger (P<.001), had lower systolic blood pressures (P=.011), and higher baseline estimated glomerular filtration rate (eGFR), (P=.027) at presentation. No differences in presenting features, imaging, urinalysis, or pathology are noted. Nontrauma cases required more antihypertensive medications (P=.001) and had higher nephrectomy rates. eGFR improved in all, but more in, trauma cases (P=.05). Through the analysis of 26 cases of Page kidney, two distinct groups were identified. Trauma patients tended to be younger, male, have less renal impairment and lower systolic blood pressure. Nontrauma patients required more antihypertensive medications and had a higher nephrectomy rate. New-onset hypertension occurred independent of etiology, calling for close surveillance of blood pressures.

An unusual presentation of a Page kidney 24 days after transplantation: case report

The Page kidney phenomenon is a well recognized entity where an extrinsically compressed kidney results in hypertension and loss of function. This compression is usually caused by a subcapsular hematoma secondary to blunt abdominal trauma or an invasive procedure such as a renal biopsy. We describe an unusual case involving the spontaneous development of a Page kidney 24 days after renal transplantation without any history of preceding trauma. The subcapsular hematoma was detected by a computerized tomographic scan performed as part of the work-up for acute allograft dysfunction. Prompt recognition and early intervention are essential if renal function is to be restored before irreversible damage occurs.